1737- Cyclone killed over 300,000 in Calcutta, India

October 7

For most of maritime history, sailing the open oceans meant captains coped with storms as a consistent threat. Such was the case in October 1737, when a storm formed in the North Indian Ocean and then went north, slamming into the mouth of the Hooghly River close to Calcutta, India. Although recent scientific studies pinpoint the storm's landfall on October 11, many people refer to October 7, 1737, as the official date the storm killed 300,000 people. So why the difference, and why should we care?

Studying these weather events gives officials time to warn people and get them out of the way. The storm surge probably caused a catastrophic loss of life, a storm surge that looked like 40-foot waves. As most of us know, hurricanes, typhoons, and tropical cyclones can be destructive forces of nature. What many may not know is these three weather phenomena are the same form of weather events. The only difference between them is where they form as in what Ocean these storms use for energy.

Meteorologists study and monitor the weather everywhere on the planet at all times using satellite imaging and other scientific instruments. The difference in what people call a storm depends on the location on the planet. The Northeast Pacific and Atlantic Oceans produce hurricanes. Formation in the Northwest Pacific Ocean means it's a typhoon. Finally, tropical cyclones form in the South Pacific and Indian Oceans.

When a cluster of clouds shows evidence of organizing around a central point of low barometric pressure, meteorologists start tracking it as a tropical depression with potential maximum sustained winds of 0 to 38 mph. If the tropical depression starts spinning fast enough, 39 to 74 mph maximum sustained winds; it's a tropical storm. If the sustained winds reach 75 mph, Meteorologists go from storm to cyclone.

Facts About the Cyclone of 1737:

  • While no one knows the exact number, experts estimate that 300,000 people died as a result of the 1737 Hooghly River Cyclone.
  • The Cyclone hit 270 km/h for one minute and 260 km/h for three minutes.
  • The Ganges accumulated 15 inches of rain in six hours.
  • The area is prone to tropical cyclones. Storms with death tolls over 10,000 were recorded in 1787, 1789, 1822, 1833, 1839, 1864, and 1876.